Groups of articles, such as containers, may be packaged by sleeving the each group of articles with a sleeve made of a shrinkable wrapping material as the articles are transported on a conveyor. In typical practice, the sleeve is applied to the group of articles with the articles nested together in an upright position, where the sleeve is applied over the top portions of the upright nested articles, and the material of the sleeve is shrunk to bundle the group of nested articles. Where it is desired to bundle the group by wrapping a portion of the sleeve around the bottom of the group of nested articles, for example, to form a base around the nested group, the group of articles is typically elevated on a pedestal or other fixture having a surface area smaller than the perimeter area of the bottom of the nested group, to allow positioning of the sleeve such that a portion of the wrapping material can be shrunk to form a base around the perimeter of the bottom of the group of nested articles. The pedestal must have a surface area sufficient to support the group of nested articles during the sleeving process, which may limit the width of the area of the bottom perimeter of the nested articles extending beyond the pedestal and exposed to be enclosed by the wrapping material to form the base of the bundled group.
Alternatively, the group of nested articles may be positioned in or on a box, a boot, or holder, a packing sheet, a tray or other supportive element, such that the supportive element is positioned on the pedestal to support the group of nested articles and the supportive element and group of nested elements are both sleeved and shrunk wrapped together to form the bundled group. The supportive element, which may be made of a paper-based material, stabilizes the nested articles and when shrunk wrapped around the bottom during the bundling process, provides a base for the bundled group. This approach consumes additional packaging material by using a supportive element in addition to the wrapping material and is less amenable to recycling by combining polymer and paper elements in the packaging which must be separated for recycling prior to disposal. The cost of this approach is increased by the cost of the additional packaging material, and the increased time and additional equipment required to position the group of nested articles in or on the supportive element prior to sleeving and shrink wrapping. The holder or supportive element may also increase the weight and footprint of the bundled group, increasing shipping and transportation costs and decreasing shelf density during storage or display of the bundled groups.
Unconstrained or minimally constrained movement and/or vibration of the nested articles as they are transported on the conveyor to be grouped for sleeving may result in misorientation of one article relative to another, sub-optimized nesting densities, and/or instability of the articles in the bundled group. Misoriented articles, especially those having irregular shapes or non-symmetrical head portions may interfere with each other reducing pack density and/or bundle stability, or may interfere with sleeving of the nested group, for example, by protruding outside the base footprint of the nested group, creating a non-uniform or misaligned appearance or affecting perceived packaging quality. Dedicated fixturing and/or equipment to position and retain the irregular shaped portions of the upright articles in an oriented arrangement during the conveying, grouping, sleeving and bundling process may reduce packaging line flexibility and/or may be cost prohibitive.